Hi Colorme, welcome to this community !

At this stage you cannot use Illustrator vector plugins. This possibility will probably be available through the open source development of Xara LX, but I am afraid not immediately.

However it's possible to use the Photoshop bitmap plugins bundled with some illustrator versions. For that, add the path to their folder in Utilities/Options/Effects&Plugins/Setup.

About Vector additions you could try the nice ones created by Dmitry Malutin and available on Gary Priester's XaraXone. They are small standalone programs which can create spirals, fractals and some vector fillings based on bitmaps and you can cut and paste them right into Xara afterwards.

kindly,
ivan